Khan.scratchpad.disable(); Christopher sells magazine subscriptions and earns $$10$ for every new subscriber he signs up. Christopher also earns a $$36$ weekly bonus regardless of how many magazine subscriptions he sells. If Christopher wants to earn at least $$44$ this week, what is the minimum number of subscriptions he needs to sell?
Solution: To solve this, let's set up an expression to show how much money Christopher will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Christopher wants to make at least $$44$ this week, we can turn this into an inequality. Amount earned this week $\geq $44$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $44$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $10 + $36 \geq $44$ $ x \cdot $10 \geq $44 - $36 $ $ x \cdot $10 \geq $8 $ $x \geq \dfrac{8}{10} \approx 0.80$ Since Christopher cannot sell parts of subscriptions, we round $0.80$ up to $1$ Christopher must sell at least 1 subscriptions this week.